An embryo (/ ˈɛmbrioʊ / EM-bree-oh) is the initial stage of development for a multicellular organism. In organisms that reproduce sexually, embryonic development is the part of the life cycle that begins …

Dec 25, 2025 · In humans the term is applied to the unborn child until the end of the seventh week following conception; from the eighth week the unborn child is called a fetus. A brief treatment of …

: an animal in the early stages of development that are marked by cleavage, the laying down of the basic tissues, and the formation of primitive organs and organ systems compare fetus. : a tiny young plant …

Oct 14, 2025 · Timing is what sets apart an embryo from a fetus. Learn more about the stages of your baby’s development here.

Dec 23, 2025 · Scientists have developed an experimental way to study how human embryos implant in a uterus, which may provide new insights into why miscarriages occur and how they can be prevented.

EMBRYO definition: 1. an animal that is developing either in its mother's womb or in an egg, or a plant that is…. Learn more.

Jul 22, 2025 · Human embryo development begins with fertilization, the union of a sperm and an egg, typically in the fallopian tube. This fusion forms a single-celled zygote, containing a complete set of …

Not only do embryos get bigger during that time, but they also go from being just a simple, single, cell to being the many cells that make up a human. All of a human’s features, organs, and body systems …

Aug 13, 2023 · In Biology, an embryo is designated as the initial phase of development for a multicellular organism arising after the fusion of a sperm cell (male sex gamete) and an egg cell (female sex …

Embryology is the study of the development of an embryo. The exact time period generally corresponding to the embryonic stage is imprecisely defined.